Abstract: ObjectiveTo studty the effect of cadmium on tissue residue of nickel and parameter of pharmacokinetics of nickel isotope tracer in rats.MethodsThe rats in six groups were intragastrically administrated with mixture of ⁶³NiCl₂ and different doses of CdCl₂,respectively.Fifteen days after the administration,the rats were sacrificed and their tail blood and tissue samples were collected.The radioactivity of the samples were detected with liquid scintillation counting.ResultsThe concentration-time curves of nickel in the blood fitted the two-dicompartment model of pharmacokinetics.After the rats were treated with single dose of nickel without cadmium,residue of nickel in almost all tisssues were higher.After the rats were exposed to both lower dose cadmium and nickle,residue of nickel in all tissues was lower.After the rats were exposed to both higher dose of cadmium(25 mg/kg)and nickel,residue of nickel in tissues was increased again.ConclusionThe obvious influence of cadmium on nickel residue in rats was found.The low dose of cadmium can inhibit absorption of nickel and the inhibition is weak for high dose of cadmium.